This post has been edited (edited parts marked [like this]) as readers were confused by the technical descriptions, I have replaced them with simpler descriptions.
The 5 hour down time was caused by a ['network trouble'] that lasted 2 hours. During those 2 hours the host did an unexpected shut down to put us in their [recovery mode] because it wasn't responsive due to the 'network trouble'.
This unexpected shut down caused the [server to break] and reinstalling everything may have been required if it wasn't for hammering in commands and hoping some would work. Luck was on our side this time and it was fixed after around 5 hours.
I've made some changes to prevent this extra downtime happening again so this shouldn't happen again next ['network trouble'].